The present invention relates to a mobile wireless apparatus and, more specifically, to a mobile wireless apparatus wherein a key sheet is easily attached by press fitting and hardly detached after fitted once.
Currently, slimming down, downsizing, and cost reduction by mass production are indispensable conditions in manufacturing of mobile wireless apparatus, and efforts are being made by each manufacturer from day to day. Therefore, the key sheet as one of its internal components is also required to be slimmed and downsized, and simultaneously, it is required to be easily attached and hardly detached even though it is slimmed, downsized, and manufactured in quantity.
However, when the key sheet is mounted to the cover of an mobile wireless apparatus in conventional manufacturing process, giving a priority to mass production may result in one of the design in which both of attachment and detachment are easily made as shown in FIG. 7, or the design in which attachment is easy but the position of installation is limited due to the layout of the packaged components as shown in FIG. 8. When mass production is not taken into account, as shown in FIG. 9, though installation is not limited by the layout of the packaged components, precise dimensioning in the structure makes it hard to be detached, but hard to be attached.
FIG. 7 to FIG. 9 are cross-sectional views showing the fitting projection formed on the cover and the fitting recess formed on the key sheet. Though there is shown a clearance between the fitting projection and the fitting recess for the purpose of explanation, the diameter G of the fitting hole as a fitting recess formed on the key sheet 23 is smaller than the outer diameter F of the fitting projection formed on the cover 21, so that the key sheet 23 is attached to the cover 21 by press-fitting the fitting projection into the fitting recess in the case of FIG. 7. Consequently, there is a problem in that it can be fitted easily, but detached easily. In addition, in FIG. 7, the height of engagement H cannot be sufficiently provided due to slimmed design thereof.
In FIG. 8, there is shown a structure in which a fitting recess is provided also around the fitting projection on the cover 31, a fitting projection is provided also around the fitting recess on the key sheet 33, the inner diameter K of the fitting recess on the key sheet 33 is determined so as to be smaller than the outer diameter J of the fitting projection formed on the cover, and the inner diameter M of the fitting recess formed around the fitting projection on the cover 31 is determined so as to be larger than the outer diameter L of the fitting projection around the fitting recess of the key sheet 33. In the example shown in FIG. 8, though the key sheet can be easily attached and the height of engagement N can be freely provided, there is a problem in that the positions to form the fitting projection and the fitting recess in order to establish the height of engagement N are limited due to the layout of the packaged components. In addition, this structure is affected by its slimmed design.
In the structure shown in FIG. 9, when a packaged component 47 is placed on the printed board 45, the key sheet 43 is provided with a clearance recess of larger size than the packaged component 47 so that the layout of the packaged components does not have effect on the design of the key sheet. However, since the outer diameter P of the fitting projection formed on the key sheet 43 is determined to be the value close to the inner diameter Q of the fitting recess formed on the cover 41 and the key sheet 43 is attached to the cover 41 by press fitting, the key sheet resists mounting and removing. In a structure shown in FIG. 9, though the height of engagement R is freely established, it is affected by the slimmed design.
The present invention is intended to solve the problems described above, and an object of the present invention is to provide a mobile wireless apparatus wherein the key sheet is easily attached to the cover by press fitting and hardly detached therefrom after fitted once.
The first aspect of the present invention is a mobile wireless apparatus having a key controlling panel constructed by joining a key sheet having key tops thereon and a cover having holes into which the key tops are inserted, wherein there are provided a first fitting recess and a first fitting projection in the first fitting recess on one of the cover and the key sheet, and a second fitting projection and a second fitting recess in the center of the second fitting projection on the other one of the cover and the key sheet so that the fitting recess and the fitting projection are press fitted when inserting the key tops into the key top holes.
This construction ensures that the key sheet is easily attached and hardly detached after fitted once.
The second aspect of the present invention is a mobile wireless apparatus according to the first aspect, wherein the first fitting projection formed on the center of first the fitting recess and the second fitting recess formed on the center of the second fitting projection are interference fitted with respect to each other. The third aspect of the present invention is a mobile wireless apparatus according to the first aspect, wherein fitting relationship between the first fitting projection formed on the center of the first fitting recess and the second fitting recess formed on the center of the second fitting projection is a interference fit, and fitting relationship other than the fitting relationship between the second fitting recess formed on the center of the center of the second fitting projection and the first fitting projection formed on the center of the first fitting recess is a clearance fit.
In this arrangement, in the invention according to the second aspect and the third aspect, the second fitting recess formed on the center of the second fitting projection is widened by the interference fit, and thus the fitting relationship therearound other than that between the first fitting recess formed in the center of the first fitting projection and the second fitting projection formed on the center of the second fitting recess becomes a interference fit, whereby the key sheet is easily fitted to the cover and hardly detached after fitted once.
The fourth aspect of the present invention is a mobile wireless apparatus having a key controlling panel constructed by joining a key sheet having key tops thereon and a cover having holes into which the key tops are inserted, wherein the cover is provided with a first fitting recess and a first fitting projection within the first recess, and the key sheet is provided with a second fitting projection and a second fitting recess in the center of the second projection, so that the fitting recess and the fitting projection is press fitted when inserting the key tops into the key top holes.
This construction ensures that the key sheet is easily attached to the cover and hardly detached therefrom after fitted once.
The fifth aspect of the present invention is a mobile wireless apparatus according to the fourth aspect, wherein the fitting projection formed in the fitting recess is a boss erecting on the cover.
This construction ensures that the key sheet is easily attached and hardly detached after fitted thereon though the structure is simple.
The sixth aspect of the present invention is a mobile wireless apparatus according to the fifth aspect, wherein the configuration of the boss is cylindrical.
This construction ensures that the key sheet is easily attached and hardly detached after fitted once.
The seventh aspect of the present invention is a mobile wireless apparatus according to the fourth aspect, wherein the fitting first recess having a first fitting projection therein formed on the cover is formed symmetrically about the vertical centerline of the cover, and the first fitting recess formed on the upper end of the cover is positioned on the left and right ends of the cover, and the first fitting recess formed on the lower end is located in the vicinity of the vertical centerline of the cover.
This construction ensures that the key sheet is easily attached and hardly detached after fitted once regardless even though only small numbers of fixing positions can be provided due to downsizing.
The eighth aspect of the present invention is a mobile wireless apparatus according to the seventh aspect, wherein the first fitting recess formed on the upper end is deeper than the first fitting recess formed on the lower end.
This construction ensures that the key sheet is easily attached and hardly detached after fitted once. The ninth aspect of the present invention is a mobile wireless apparatus according to the fourth aspect, wherein the fitting projection having a second fitting recess in the center formed on the key sheet is hollow cylindrical shape formed of the same material as the key sheet.
This construction ensures that the key sheet is easily attached and hardly detached after fitted once though the construction is simple.
The tenth aspect of the present invention is a mobile wireless apparatus according to the ninth aspect wherein the key sheet is formed of silicone rubber.
This construction ensures that the key sheet is easily attached and hardly detached after fitted once though the construction is simple.
The eleventh aspect of the present invention is a mobile wireless apparatus according to the fourth aspect, wherein the second fitting projection having a second fitting recess in the center formed on the key sheet is formed symmetrically about the vertical centerline of the key sheet, and the second fitting projection formed on the upper end is positioned on the left and right ends of the key sheet, and the second fitting projection formed on the lower end is located in the vicinity of the vertical centerline of the key sheet.
This construction ensures that the key sheet is easily attached and hardly detached after fitted once even though only small numbers of fixing positions can be provided due to downsizing.
The twelfth aspect of the present invention is a mobile wireless apparatus according to the eleventh aspect, wherein the second fitting projection formed on the upper end thereof is higher than the second fitting projection formed on the lower end thereof.
This construction ensures that the key sheet is easily attached and hardly detached after fitted once.